I confirm this. Not sure this has anything to do with the card layout. I think Sencha guys use macs and iphones and simply ignore this problem which is already there for 1.5 years.
Not sure how to fix this though. For me it works sometimes. E.g. you focus the field, keyboard appears, it goes up. You remove the focus, everything goes back. You do it again - keyboard covers the input. It just behaves randomly.